Fundamentals of Meat Hygiene(Parts 1,2,3,and4.doc
Fundamentals Of Meat Hygiene
By
Elsaid A. Eldaly Professor of Meat Hygiene Chairman of Food control Dept. Faculty of Veterinary Medicine Zagazig University
Fundamentals of Meat Hygiene(Parts 1,2,3,and4.doc
Preface For a number of last years, technological developments in the meat and meat products industry have been underpinned by parallel developments in understanding of the related chemistry and microbiology. For this reason, it is apparent that a full appreciation of the science of meat and meat products requires knowledge of the basic disciplines: Technology, chemistry and microbiology in addition to pathology, parasitology, physiology, anatomy, public health and psychology. The quality assurance of meat and meat products has been the ultimate goal of all food hygienists. This accordable assurance has extended over a long complicated operations starting at breeding of food animal to the point of consumption of its wholesome meat and meat products. In writing these notes (Fundamentals of Meat Hygiene), we have tried to present an account on meat hygiene that is both thorough and accessible. Since our subject is broad, covering a diversity of topics from production to consumption (by way of pre-slaughter care, slaughtering and preparation operations, anteand post-mortem examinations, affections, pathological, microbial, parasitic diseases and their decisions, meat spoilage, its causes and prevention, meat preservation, meat microbiology, residues and food poisoning etc...). This can make presentation of a coherent treatment difficult, but it is also part of what makes meat hygiene course such an interesting and challenging subject. Traditionally, food production was generally regarded as being the responsibility of the ministry of agriculture, whereas food hygiene and other aspects of food safety were the responsibility of the ministry of health. However, further ministries (e.g. social affairs interior, trade, industry etc...) are
Fundamentals of Meat Hygiene(Parts 1,2,3,and4.doc also involved in one way or another in food control. This can easily lead to unnecessary duplication of work, conflicting interests, unclear and complicated regulations and legal uncertainties. This coordination of various food control activities is therefore a necessity. In addition, the veterinary food hygienists should take their active role and the responsibility in supervision, examination and decision on hygiene and safety of food especially those of animal origin in every where beside that he must has the ability to judge and condemn the meat and/or meat products which are unfit for human consumption. It is hoped, that, these notes will serve as a valuable reference for students (undergraduate and postgraduate) and field governmental officials directly or indirectly connected with hygiene and safety of meat and meat products. Generally, I am grateful to all members of food hygiene departments in all veterinary faculties, especially to the staff of meat hygiene and specifically to those whom encouraged and taught me how the scientific research is. I do not profess to have an expert knowledge in all the various disciplines that I have brought together in these notes, and I hope the mistakes that I have made will not cause too much grief.
Elsaid A. Eldaly
Fundamentals of Meat Hygiene(Parts 1,2,3,and4.doc CONTENTS (Part I) 1. 2.
Preface Introduction
i 1
3. 4.
Meat producing animals Slaughter animal The structure of muscle Chemical composition and nutritional value of
2 3 4 8
meat (i) Chemical composition of meat (ii) Nutritional value of meat
8 13
6.
Slaughterhouses (Abattoirs) (i) Construction of Abattoirs (ii) Slaughterhouse sanitation Pre-slaughter care
15 15 29 40
7.
(i) Care on the farm (or production unit) (ii) Care during transportation (iii) Care on markets (iv) Care during lairaging in the slaughterhouse Ante-mortem Examination
40 41 47 48 51
Slaughtering and preparation of slaughtered animals (i) Kinds of slaughter
54 54
(ii) Methods of slaughter (iii) Emergency and causality slaughter Bleeding of animals Dressing of carcasses (i) Traditional system
55 62 66 70 70
5.
8.
9. 10.
(ii) Modern line dressing system
71
Fundamentals of Meat Hygiene(Parts 1,2,3,and4.doc
11.
(iii) Carcass yield Post-mortem inspection of carcasses (i) P.M. examination of beef and camel carcasses (ii) P. M. examination of calves (iii) P. M. examination of sheep and goat
75 76 77 81 81
Contents (iv) P. M. examination of pigs (v) Decisions at post-mortem examination 12.
82 82
Lymphatic system Butcher's joints in relation to the carcass lymph nodes Marking of carcasses
102
14.
Post-mortem changes (i) Rigor-mortis. (ii) Enzymatic autolysis (Proteolysis). (iii) Development of drip.
104 104 114 116
15.
Characters and identification of carcass species (i) Determination of age. (ii) Determination of sex (ii) Characteristics of meat and fat. (iv) Differentiation of carcasses of slaughtered animal
118 118 122 127 131
13.
a) Marking of carcasses b) Anatomical differences.
16.
(v) Differentiation of meat and fat. a) Chemical means. b) Biological means. Pathological conditions and body disturbances (i) Pathological conditions.
87 99
131 131 133 133 135 140 141
Fundamentals of Meat Hygiene(Parts 1,2,3,and4.doc
17.
(ii) Body disturbances Affection of specific parts (i) Head and tongue (ii) Lung and pleura (iii) Heart (iv) Liver (v) Kidneys (vi) Spleen
151 170 170 170 173 175 177 180
Contents 16.
Parasitic diseases (i) Parasites directly transmissible to mans (ii) Parasites indirectly transmissible to man (iii) Parasite not transmissible to man
181 181 194 198
19.
Specific diseases (Bacterial, Viral and Fungal diseases) 1- Tuberculosis 2- Jรถhne's disease (paratuberculosis) 3- Actinomycosis (Lumpy jaw)
208 208 221 222
4- Actinobacillosis (wooden tongue) 5- Caseous lymphadenitis 6- Anthrax. 7- Brucellosis 8- Compylobacteriosis
223 224 225 226 228
9- Colibacillosis (white scour, omphalophlebitis) 10- Contagious Bovine pleuropneumonia (CBPP) 11- Contagious Caprine pleuropneumonia (CCPP)
229 229 230
12- Salmonellosis
230
Fundamentals of Meat Hygiene(Parts 1,2,3,and4.doc 13- Calf diseases 14- Haemorrhagic septicaemia of cattle 15- Leptospirosis. 16- Listeriosis (Circling disease).
231 232 232 233
17- Swine erysipelas 18- Bacillary haemoglobinuria (red water disease) 19- Black quarter (Blackleg) 20- Enterotoxaemia (Pulpy kidney disease)
233 235 235 236
21- Lamb dysentery 22- Tetanus (Lockjaw) Viral disease 1- Foot and mouth disease 2- Rinderpest (Cattle plague)
236 236 237 237 238
Contents 3- Rabies 4- Pox disease 5- Rift valley fever (Enzootic hepatitis) 6- Lumpy skin disease Other specific disease a) Scrapie
238 240 240 241 241 241
b) Bovine Spongiform Encephalopathy (BSE) Disease caused by fungi
242 242
1- Aspergillosis 2- Coccidioidomycosis 3- Ochratoxicosis
242 243 243
Fundamentals of Meat Hygiene(Parts 1,2,3,and4.doc
CONTENTS (Part II) Page 1- Preface 2- Introduction 3- Meat microbiology (i) Causes of food spoilage (ii) Factors that affect microbial growth in food (iii) Microbial contamination of meat (iv) Decomposition and spoilage of meat (v) Types of bacterial spoilage (a) Surface slime (b) Meat putrefaction (c) Other kinds of bacterial spoilage of meat (vi) Decomposition of fat (vii) Control of spoilage of meat 4- Prophylactic measures to produce high quality meat 5- Bacteriological examination of carcasses 6- Microbial food borne diseases A) Food borne infection (i) Salmonellosis (ii) Pathogenic Escherichia coli (iii) Shigellosis (Bacillary dysentery) (iv) Yersiniosis (v) Campylobacteriosis (vi) Listeriosis (vii) Vibrio (viii) Enteric viruses B) Food borne intoxication (i) Staphylococcal food poisoning (ii) Botulism (iii) Mycotoxicosis C) Food borne toxicoinfection (i) Clostridium perfringens gastroenteritis (ii) Bacillus cereus
i iii 1 1 3 14 20 27 27 28 32 8 40 43 45 49 53 54 57 62 63 65 67 70 72 74 75 78 81 82 82 85
Fundamentals of Meat Hygiene(Parts 1,2,3,and4.doc Page 7- The storage and preservation of meat (i) Drying (dehydration) (ii) Food additives (iii) Curing (iv) Smoking (v) Cold preservation a) Ice chilling b) Chilling c) Freezing (vi) Canning (vii) By irradiation (viii) By antibiotics 8- Chemical residues in meat (detection & public health) (i) Drug residues (ii) Growth promoting substances (iii) Heavy metals and other trace elements (iv) Pesticide residues (v) Nitrate, nitrite and N-nitrosamines (vi) Toxicants occurring in food 9- Packaging
88 89 89 105 111 116 120 121 127 145 166 170 173 175 182 187 190 193 195 199
Fundamentals of Meat Hygiene(Parts 1,2,3,and4.doc CONTENTS (Part III) Page 1- Preface i 2- Introduction iii Chapter [1] 3- Poultry meat (Hygiene and inspection) 1 (i) Introduction 1 (ii) Chemical composition 7 (iii) Nutritive value 11 (iv) Construction and layout of poultry processing plant (v) Ante-mortem inspection of poultry 21 (vi) Slaughtering and dressing techniques 24 (vii) Post-mortem inspection of poultry 35 (viii) Microbiology of primary processing of poultry 40 (ix) Diseases of poultry 42 a) Bacterial diseases 42 b) Viral diseases 48 c) Fungal diseases 51 d) Parasitic diseases 52 e) Miscellaneous diseases 54 4- Rabbit meat (i) Slaughter and carcass dressing 56 (ii) Diseases of rabbits 57 a) Bacterial and fungal diseases 57 b) Viral diseases 59 c) Parasitic diseases 59 Chapter [2] 5- Fish and shellfish 62 (i) Introduction 62 (ii) Morphology 64 (iii) Improper fishes (invertebrates) 74 (iv) Class crustaceans 74 (v) Phylum Mollusca 79 (vi) Chemical composition and nutritive value 85 a) Chemical composition of fish 85 Page b) Nutritive value of fish
92
15
Fundamentals of Meat Hygiene(Parts 1,2,3,and4.doc (vii) Post-mortem changes in fresh fish a) Mucus secretion b) Rigor-mortis c) Autolysis d) Spoilage of fish and shellfish (viii) Poisoning by fish and shellfish a) Bacterial food poisoning b) Biogenic amines c) Algal toxins d) Viral contamination of shellfish e) Biotoxication (ix) Preservation of fish and shellfish a) By chilling b) By freezing c) By smoking d) By salting e) By canning f) By radiation g) By antibiotics (x) Examination of fish and shellfish (xi) Examination of frozen fish (xii) Examination of smoked fish (xiii) Examination of salted fish (xiv) Examination of fish conserves (xv) Caviar
94 94 95 96 97 106 107 110 112 114 115 119 119 121 126 127 129 130 131 131 137 137 139 141 144
Fundamentals of Meat Hygiene(Parts 1,2,3,and4.doc CONTENTS (Part IV) Animal by products Page 1.Preface 2. Introduction 3. Sources of animal by- products 4. Methods of treatment (i) Wet- rendering (ii) Dry-rendering 5. Hygienic construction of by- product plants 6. Utilization of blood 7. Hides and skins 8. Utilization of bones 9. Gelatin and glue 10. Horns and hoofs 11. Hair and bristles 12. Wool 13. Stomach and intestines 14. Minor by- products 15. Endocrine glands 16. Bile and gallstones 17. Production of methane gas 18. Poultry by- products 19. Fish - by- products
Elsaid A. Eldaly Professor of Meat Hygiene Chairman of Food control Dept. Faculty of Veterinary Medicine Zagazig University
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